Steering apparatus

Abstract

The steering apparatus includes an inner column, a left-right pair of outer column half bodies, a fixing bracket having fixing side portions, and a clamping tool. In a condition where the inner column is clamped fixedly via the clamping tool, the inner column is held by the holding surface portions of the two outer column half bodies, and an upper recessed indentation portion and a lower recessed indentation portion that do not contact the inner column are formed on the respective holding surface portions of the two outer column half bodies. Strip-form contact portions that contact the inner column are formed in locations on either circumferential direction side of the upper recessed indentation portion and the lower recessed indentation portion, the strip-form contact portions being formed in at least four locations on the two outer column half bodies.

What is claimed is: 
     
       1. A steering apparatus comprising:
 an inner column; 
 a left-right pair of outer column half bodies respectively having holding surface portions for holding an outer peripheral surface of the inner column; 
 a fixing bracket having fixing side portions that sandwich the outer column half bodies; and 
 a clamping tool that clamps the fixing bracket and the two outer column half bodies, 
 wherein, in a condition where the inner column is clamped fixedly via the clamping tool, the inner column is held by the holding surface portions of the two outer column half bodies, 
 an upper recessed indentation portion and a lower recessed indentation portion that do not contact the inner column are formed on the respective holding surface portions of the two outer column half bodies, 
 strip-form contact portions that contact the inner column are formed in locations on either circumferential direction side of the upper recessed indentation portion and the lower recessed indentation portion, 
 the strip-form contact portions are formed in at least four locations on the two outer column half bodies, 
 wherein respective centers of curvature of the upper recessed indentation portion and the lower recessed indentation portion differ from an axial center of the inner column. 
 
     
     
       2. The steering apparatus according to  claim 1 , wherein the strip-form contact portions are formed to extend in an axial direction of each of the outer column half bodies. 
     
     
       3. The steering apparatus according to  claim 1 , wherein a tip end of each of the strip-form contact portions has an arc-shaped cross-section. 
     
     
       4. The steering apparatus according to  claim 1 , wherein the strip-form contact portions of the outer column half bodies exhibit left-right symmetry about a diametrical center of the inner column. 
     
     
       5. The steering apparatus according to  claim 1 , wherein the strip-form contact portions exhibit vertical symmetry about a diametrical center of the inner column. 
     
     
       6. The steering apparatus according to  claim 1 , wherein the upper recessed indentation portion and the lower recessed indentation portion are constituted by recessed arc-shaped surfaces having a smaller radius of curvature than an outer diameter of the inner column. 
     
     
       7. A steering apparatus comprising:
 an inner column; 
 a left-right pair of outer column half bodies respectively having holding surface portions for holding an outer peripheral surface of the inner column; 
 a fixing bracket having fixing side portions that sandwich the outer column half bodies; and 
 a clamping tool that clamps the fixing bracket and the two outer column half bodies, 
 wherein, in a condition where the inner column is clamped fixedly via the clamping tool, the inner column is held by the holding surface portions of the two outer column half bodies, 
 an upper recessed indentation portion and a lower recessed indentation portion that do not contact the inner column are formed on the respective holding surface portions of the two outer column half bodies, 
 strip-form contact portions that contact the inner column are formed in locations on either circumferential direction side of the upper recessed indentation portion and the lower recessed indentation portion, 
 the strip-form contact portions are formed in at least four locations on the two outer column half bodies, 
 wherein the strip-form contact portions of the outer column half bodies exhibit left-right symmetry about a diametrical center of the inner column, and 
 wherein the upper recessed indentation portion and the lower recessed indentation portion are constituted by recessed arc-shaped surfaces having a smaller radius of curvature than an outer diameter of the inner column. 
 
     
     
       8. The steering apparatus according to  claim 7 , wherein the strip-form contact portions exhibit vertical symmetry about a diametrical center of the inner column. 
     
     
       9. The steering apparatus according to  claim 7 , wherein the strip-form contact portions are formed to extend in an axial direction of each of the outer column half bodies. 
     
     
       10. The steering apparatus according to  claim 7 , wherein a tip end of each of the strip-form contact portions has an arc-shaped cross-section. 
     
     
       11. A steering apparatus comprising:
 an inner column; 
 a left-right pair of outer column half bodies respectively having holding surface portions for holding an outer peripheral surface of the inner column; 
 a fixing bracket having fixing side portions that sandwich the outer column half bodies; and 
 a clamping tool that clamps the fixing bracket and the two outer column half bodies, 
 wherein, in a condition where the inner column is clamped fixedly via the clamping tool, the inner column is held by the holding surface portions of the two outer column half bodies, 
 an upper recessed indentation portion and a lower recessed indentation portion that do not contact the inner column are formed on the respective holding surface portions of the two outer column half bodies, 
 strip-form contact portions that contact the inner column are formed in locations on either circumferential direction side of the upper recessed indentation portion and the lower recessed indentation portion, 
 the strip-form contact portions are formed in at least four locations on the two outer column half bodies, 
 wherein the strip-form contact portions exhibit vertical symmetry about a diametrical center of the inner column, and 
 wherein the upper recessed indentation portion and the lower recessed indentation portion are constituted by recessed arc-shaped surfaces having a smaller radius of curvature than an outer diameter of the inner column. 
 
     
     
       12. The steering apparatus according to  claim 11 , wherein the strip-form contact portions are formed to extend in an axial direction of each of the outer column half bodies. 
     
     
       13. The steering apparatus according to  claim 11 , wherein a tip end of each of the strip-form contact portions has an arc-shaped cross-section. 
     
     
       14. A steering apparatus comprising:
 an inner column; 
 a left-right pair of outer column half bodies respectively having holding surface portions for holding an outer peripheral surface of the inner column; 
 a fixing bracket having fixing side portions that sandwich the outer column half bodies; and 
 a clamping tool that clamps the fixing bracket and the two outer column half bodies, 
 wherein in a condition where the inner column is clamped fixedly via the clamping tool, the inner column is held by the holding surface portions of the two outer column half bodies, 
 an upper recessed indentation portion and a lower recessed indentation portion that do not contact the inner column are formed on the respective holding surface portions of the two outer column half bodies, 
 strip-form contact portions that contact the inner column are formed in locations on either circumferential direction side of the upper recessed indentation portion and the lower recessed indentation portion, 
 the strip-form contact portions are formed in at least four locations on the two outer column half bodies, and 
 wherein the upper recessed indentation portion and the lower recessed indentation portion are constituted by recessed arc-shaped surfaces having a smaller radius of curvature than an outer diameter of the inner column. 
 
     
     
       15. The steering apparatus according to  claim 14 , wherein the strip-form contact portions are formed to extend in an axial direction of each of the outer column half bodies.